The invention described herein arose in the course of, or under, contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.
The present invention relates generally to optical components for use in conjunction with lasers, and more particularly to an improved means for aligning laser relay optics.
During assembly and alignment of relay optics for a laser optical transport system, proper relay of the input (such as a mask) throughout the system is a primary objective, since this arrangement keeps the beam in the near field and, thus, avoids diffraction effects where the beam is used. Current means of achieving this goal include using outputs from a commercially available optical ray tracing software package and/or the use of various masks, such as the corners of cards or wires, placed in the beam at intermediate pupil planes, the pupil planes being planes intersecting the laser beam where the input pupil is imaged. In addition, a little luck and a great deal of patience is required to achieve proper alignment. The quality of alignment eventually obtained is limited by patience and eye strain and is, at the best, a subjective decision.
Clearly, it would be advantageous to have a more precise means for aligning a laser optical relay system. However, to date practitioners have suffered the tedious and imprecise method and means heretofore described, there being no available remedy to make the task either easier or better accomplished.
Split-field imagers are known in the art, and have been used in a variety of applications, as in rangefinder devices, including those found in cameras. However, to the inventor's knowledge, no prior art split-field imaging devices have been adaptable for use in aligning laser relay optics, and all prior art split-field imaging configurations have been inappropriate for this purpose.
No method or means for aligning laser relay optics, to the inventors' knowledge, has successfully provided an effective means for alignment which did not require a subjective assessment of alignment on the part of the user. Furthermore, no prior art means for aligning laser relay optics known to the inventor has provided an indication of the direction in which the optical components are misaligned. All prior art laser relay optics alignment methods have required the user to visually align the slit through the transport optics with, at best, some crude alignment reference placed in the beam path.